1. Field of the Invention
The present invention relates to a recording apparatus such as a copying machine, and more particularly to a color image recognition apparatus capable of judging whether an original is a monochromatic one or a color one based on image data which is obtained by reading the original.
2. Description of the Background Art
Generally, in color image recording apparatus, especially full color duplicating machines, since full color copies are expensive, such a mode selection is carried out that image data on an original are read out during a prescanning operation, a judgement is made whether the prescanned original is color or not based on the read image data, and a decision is made whether a color copying operation should be performed or not in response to the result of judgement.
To carry out the discrimination of color of the original, it has been proposed in Published Unexamined Japanese Patent Application No. 249365/1990 that, the original is divided into a plurality of blocks each including 3.times.3 pixels for instance so that each of the block is subjected to judgement whether the block is of chromatic or monochromatic(achromatic), and then it is judged according to a ratio of the number of monochromatic blocks to the total number of pixels whether the original is of chromatic or not. Also, there has been proposed in Published Unexamined Japanese Patent Application No. 144566/1990 that color discrimination is carried out for each pixel in white, achromatic color and chromatic color to thereby judge whether an original is of chromatic or monochromatic, and then color data concerning a color original is discriminated based on the result of judgement.
However, the above described conventional systems are disadvantageous in that the color image recognition processing is complicated resulting in making the hardware arrangement thereof complex and in prolonging the processing period of time. Further, there may occur difficulties that it is difficult to distinguish among colors having low chroma, and more specifically it is difficult to discriminate blackish colors such as dark brown. Furthermore, there may occur another difficulty to perform color discrimination with high accuracy in case of an area to be subjected to the color discrimination being relatively small.